Taxonomic analysis of Chinese power transmission and distribution industry accidents based on hazard components

Power transmission and distribution were critical components for the development of Chinese economy. As in all sectors of the economy it was important to reduce the accidents rate as low as possible. This research adapted accident taxonomic analysis to identify the main factors associated with accidents and then provided accident prevention countermeasures in the industry in China. Because of lack of systematic power transmission and distribution accident information in China, 324 power grid accidents from 1961 to 2008 were collected through a wide range of sources and classified according to hazard elements which were target and threat, hazard element and initiating mechanism respectively and then the initiating mechanisms were further classified by hazard types. Through taxon structures the direct and indirect factors were identified in the industry accidents and strategies of accident prevention were recommended based on them. The taxon structures also can be further developed to form tailored safety checklist for the front workers.     

表达绿色荧光蛋白基因的花鲈胚胎干细胞株的建立及其体外分化

以带有绿色荧光标记的基因(pCMV-EGFP)为报告基因,用Genejammer、Genejuice和Metafectene三种脂质体介导花鲈胚胎干细胞(LJES1)的基因转移.实验发现,Genejammer介导的细胞转化效率最高,高达27.3%,其余分别为12.1%和5.3%.转移绿色荧光蛋白(GFP)基因的LJES1细胞经过药物筛选和单克隆化培养,获得了表达GFP基因的阳性克隆细胞株,经PCR对GFP阳性细胞株的基因组DNA及提取的RNA扩增,获得了目的条带,证实了GFP基因已经整合到LJES1细胞的基因组中,并获得了正常的表达.通过体外诱导,GFP阳性细胞能够分化为神经细胞、肌肉细胞、成纤维细胞等,用悬滴法培养获得了GFP阳性细胞的拟胚体,证实了经过长期的药物筛选后,LJES1细胞仍然保持着发育的多能性.这一研究,为进一步利用海水鱼类胚胎干细胞进行遗传操作及基因工程的研究提供了方法上的探索.     

现代海底热液活动异常条件探测关键技术研究

结合我国863计划海底热液活动探测技术研究课题的开展情况,综述了现代海底热液活动调查和研究依赖的主要探测技术--深海拖曳式走航连续探测技术、海底原位探测技术、长期定点连续探测技术、深潜技术及深海钻探技术的研究和应用,介绍了我国深海探测技术的研究现状,分析了21世纪海底热液活动研究的发展趋势,指出调查发现新的热液硫化物分布区、研究热液活动的生命现象、建立海底热液活动现场长期监测体系将会是今后研究的重点.     

脂质体对牙鲆淋巴囊肿病毒核酸疫苗免疫活性的影响

将淋巴囊肿病毒核酸疫苗pEGFP-N2-LCDV0.6kb用脂质体梭华-SoftastTM包裹后肌肉注射入牙鲆体内,通过测定牙鲆外周血、肠、脾脏和前肾的淋巴细胞增殖反应、呼吸爆发活性以及抗体产生水平,评价脂质体对pEGFP-N2-LCDV0.6kb免疫活性的影响.结果表明,脂质体可显著增强该核酸疫苗的免疫活性和提高保护率,可作为一种有应用前景的核酸疫苗佐剂.     

盐度突降对栉孔扇贝(Chlamys farreri)抗病力指标的影响

通过室内模拟实验研究了海水盐度突降对栉孔扇贝抗病力的影响.设盐度20、25两个处理,以盐度31为对照.将扇贝从盐度31的暂养海水直接转到设计盐度,分别于0h、1h、4h、12h、24h、48h、72h采血分析血细胞数目、血浆蛋白含量、超氧化物歧化酶(SOD)活性、酸性磷酸酶(ACP)活性.72h注射细菌攻毒,记录存活率.结果表明,盐度突降使血细胞数和SOD活性总体下降,而血浆蛋白含量和ACP活性总体升高.攻毒引起的上述抗病力指标的变化趋势与盐度突降相同,但处理组的响应幅度均低于对照,存活率显著降低.上述结果说明盐度突降损害了栉孔扇贝抵抗感染的能力.     

北极太平洋扇区深海沉积物的细菌多样性研究

对北极太平洋扇区4个站位深海表层沉积物样品,采用PCR结合变性梯度凝胶电泳(PCR-DGGE)技术进行了细菌16S rRNA基因V3区序列的系统发育分析.结果表明,沉积物中的细菌多样性丰富,获得的40条序列归属于4个细菌类群:变形细菌(Proteobacteria,占全部序列的75%)、噬纤维菌-屈挠杆菌-拟杆菌群(Cytophaga-Flexibacter-Bacteroides,CFB,占10%)、放线细菌(Actinobacteria,占10%)和酸杆菌(Acidobacteria,占5%).其中变形细菌(包括α、β、γ和δ-Proteobacteria),而γ-Proteobacteria占全部序列的62.5%,是很明显的优势类群.在这些细菌类群中,β、γ-Proteobacteria在4个站位沉积物中均有分布.     

拖曳式多参数剖面测量系统波浪式运动的控制

通过建立拖曳系统的运动方程和利用流体动力试验确定参数等步骤,获得了精确的拖曳系统运动模型,在此基础上,研究、设计了一种基于PID控制器的波浪运动控制方法,实现了对拖曳式多参数剖面测量系统波浪式运动的控制,并通过计算仿真和湖试验证了控制方法的合理性和可行性.结果表明,在该方法控制下,波浪式拖曳系统运动性能达到了预定设计要求.在拖曳速度为6～9节的情况下,能够控制拖曳系统按预定轨迹进行波浪运动,同时保持较稳定的姿态.     

Sequence determination of sulfated carrageenan-derived oligosaccharides by high-sensitivity negative-ion electrospray tandem mass spectrometry

Negative-ion electrospray tandem mass spectrometry with collision-induced dissociation is assessed for sequence determination of multiply sulfated oligosaccharide fragments of carrageenan obtained from partial depolymerization of the polysaccharides by either enzymatic digestion or mild acid hydrolysis. Carrageenan oligosaccharides with homogeneous disaccharide compositions were used to establish their fragmentation pattern, which was then applied to sequence determination of unusual oligosaccharides with either "hybrid" biose compositions or odd-numbered residues. As sulfate groups are labile, sulfate loss during collision-induced association was prevented by sodium adduction. The product ion spectra of [M - Na]- (where M represents the sodium salt of oligosaccharides) feature an extensive series of B- and C-type glycosidic cleavages, whereas the Y-type cleavage occurs mainly at the sulfated residues. The assignment of reducing or nonreducing terminal fragments was assisted by oligosaccharide reduction and the product ion spectra of the derived alditols. Due to the anionic nature of the sulfate present, high-sensitivity detection (1-5 pmol, using a hexasaccharide as an example) was obtained.     

β-琼胶酶AgaB催化活性的定向进化

用体外定向进化技术提高了β-琼胶酶AgaB热稳定突变酶M446的催化活性。采用易错PCR和化学诱变法相结合的方法,构建了M446的突变体文库;利用琼胶酶降解琼胶在平板上产生水解圈的特性,建立了阳性克隆的高通量筛选体系。最终筛选得到酶活性得到提高且保持较高耐热性的突变酶M117,其酶活提高为突变酶M446的3倍。测序分析发现编码突变酶M117的DNA序列中有4处点突变,其中2处为同义突变,另外2处引发氨基酸替换,分别为R9K和1111V。对突变酶M117与M446的动力学常数进行了比较,发现M117的Km值降低了93.4％,Kcat／Km值提高了15倍,由此可以推断突变酶M117比活力提高的主要原因是酶与底物的亲和能力提高。